Phonograph reproducer



Aug. 18, 1931. w. H. EDWARDS 1,819,083

PHONOGRAPH REPRODUCER Filed may 14, 1929 20 f um [Illlliwl lNvE g Wwam SATTORNEY Patented Aug. 18, 1931 Url-ED STATES.

wIELrAM'H. EDWARDS, or GREAT NECK, NEW YoEKg-Assrenon fro, AMERICANTELE- PHONE .ann rEE-EGEAPH .eoMPAnx .aoon-poaa'rron OE `NEW YORK oPHONOGEAPH Application led May 114,l

acter tor stress will vary its impedance in the` circuit. In accordancewith the arrangements of this invention, the' stress to which ation of aphonograph needle arm attached thereto. Under such' conditions, thearrangements may operate as a reproducer of sounds recorded on aphonograph record." Gther objects and features of the invention willappear more 'fully from the detailed description thereof hereinaftergiven.

For purposes of illustration,` it will bea-s4 sumed that the elementwhose impedanceis to be varied by the method of'this invention' may be arectifier ofthe well known copper oxidetype. However, other types ofthin film or Contact rectiers may be utilized. One of the suitablemethods of forming the rectifier element might consist ink heating acopper sheet about .005 thick to over 1000o C. until a thin closelyadherent layer of cuprous oxide about one or two thousandths of an inchis formed. A. heat treatment is then administered at lower temperatures.The outer surface of the oxide may then be reduced to metallic copper byelectrolysis. The impedance element in the circuit might be formed ofone or more of such units.

At the junction of the bulk of the cuprous oxide and the other copperthere is believed to be a transition layer wherein the copper oxidecrystals match perfectly the copper crystals which they adjoin. Thistransition layer is of high resistivity butin formation is made to matchon to the copper in such a way (probably with considerable stress in thetransition layer) as to reduce to a lowT value the work functionv ofescape into it of electrons from the copper. However,

is subjected to external stress. It has been the devicel is subjected iscaused by the oper- EEraoDU-OER.-

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it matches onto thel adjoining euprous oxide 1n' such va way 'as torlmake "alarge' work function.` There is no such effect between the-thinmetallic'copper on rthe outer surface of the o-Xid'e as between themother copper and theoxide due tothe different mannerin whiehit isformed. VBased on the theoryof"` a transition layer'depending uponlnitial stresses or on substantially perfectly matched crystals, it isproposed in accordance with the principles of this invention to vary thestresses iin this transition layer or the manner in which Vthe crystalsare matched and thus vary the work functions. Inasmuch as the oxide andsurface coating of copper are very thin, the transition layer isn-earthe surface of the rectifier plate and is subject' to` approximatelyvthe maximum fibre stresses existing in the plate when it is iiexed.'Furthermore; when a portion of the plate bends in one direction, thetransition layer has tensioirstresses superimposed on the initialstresses, and when bent the other.

way, has compression `stresses added tov it. It has'been'found byexperiment that bending" a plate-so thatthe oxide is placed' in tensioninstantly increases .the resistance in the reverse direction and thatwhen placed in compression-, the opposite occurs. It has also been foundthat variations .in pressure cause variations' in resistance in theconducting' direction.` Also, if kept within proper respondingstresstothedi's'k, thus bending i f it and subjecting its parts Ato tensionand compression. A"This will 'vary its impedance in the circuit inaccordance vwith the indentations on the phonograph record.'Byconnecting the circuit to loud speaker appara- Similar referencecharacters have been uti.

lized to denote like parts in all of the figures.

In Fig. 1 is shown a circuit1in-Which is connected the stressed thinfilm rectifier disk 2. A phonograph needle 'arm' 3 is shown affixed tothe central portionof this disk, as Will be pointed out hereinafter.r

The circuit also includes battery 4,21 switch 6, a variable resistance 5for Ycontrolling. the current fioW and the Winding of a transformer 7.The other winding of the transformer 7 will be .included in a circuit 8Which may lead toloud speaker apparatus.

In Fig. 3 is shown a side view of the device of the invention utilizedas a phonograph reproducer. Fig. 2 is a sectional view of thearrangements of Fig. 3 along the lines A-A. Similar reference charactershave been utilized to denote like parts in both figures. In thesefigures there is shown a base member 9, a turn-table 10 and a phonographrecord 11 mounted on the turn-table.V

A swivel support 12 is provided for the reproducer arm 18 of the device.Mounted in the reproducer arm 18 is the rectifier disk 20. This diskwill be surrounded at its periphery by the metallic contact rings 19,one on each side of said disk.

. contact rings Will be held in place by a soft The disk .and

`controlled .by said needle holder for subjecting said disk to stressesby bending and thereby varying the impedance of the disk. 2. Anelectrical phonograph reproducer 'including' a thin film rectifier disk,and

means for varying the impedance of said disk by subjecting it to bendingstresses in accordance. With recorded sound.

3. An electrical phonograph reproducer including a thin film vrectifierdisk, and means for varying the impedance of said diskby subjecting itto stress by bending, said means comprising a phonograph needle armassociated with said disk.

4. An electrical phonograph reproducer including a thin film rectifierdisk, and means for varying the impedance of said disk by subjecting itto stress by bending, said means comprising an arm with fulcrum movementhaving one extremity connected to said disk and the other extremityunder control of a sound record. j I 5. An electrical phonographreproducer including a contact rectifier of the electronic variety, asound record, and means controlled by said sound record for subjectingsaid rectifier to stresses by bending and thereby varying its impedance.

In testimony whereof, I have signed m name to this specification this11th day of May, `1929. i Y

v WILLIAM H. EDVARDS.

'ill

i no

needle caused by the indentations on the v record Will cause the needlearm to impart to the rectier disk certain stresses. Y.In other Words,the disk will be caused to bendrin accordance With the indentations onthe record. n As has been previously pointed out, this subjecting of thedisk' to stresses Will vary its impedance in a circuit. The disk isYconnected to a circuit by means ofthe flexible conductors 22 fastened toeach of the contact rings and Vcarried through the reproducer arm to thebalance of the circuit, as indicated in Fig. 1. By thus varying theimpedance of the rectifier disk by means of the phonograph needleattachment, the arrangements may be utilized as a phonograph reproducer.

